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bfa83a9e TG |
1 | #ifndef __NET_NETLINK_H |
2 | #define __NET_NETLINK_H | |
3 | ||
4 | #include <linux/types.h> | |
5 | #include <linux/netlink.h> | |
6 | ||
7 | /* ======================================================================== | |
8 | * Netlink Messages and Attributes Interface (As Seen On TV) | |
9 | * ------------------------------------------------------------------------ | |
10 | * Messages Interface | |
11 | * ------------------------------------------------------------------------ | |
12 | * | |
13 | * Message Format: | |
14 | * <--- nlmsg_total_size(payload) ---> | |
15 | * <-- nlmsg_msg_size(payload) -> | |
16 | * +----------+- - -+-------------+- - -+-------- - - | |
17 | * | nlmsghdr | Pad | Payload | Pad | nlmsghdr | |
18 | * +----------+- - -+-------------+- - -+-------- - - | |
19 | * nlmsg_data(nlh)---^ ^ | |
20 | * nlmsg_next(nlh)-----------------------+ | |
21 | * | |
22 | * Payload Format: | |
23 | * <---------------------- nlmsg_len(nlh) ---------------------> | |
24 | * <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) -> | |
25 | * +----------------------+- - -+--------------------------------+ | |
26 | * | Family Header | Pad | Attributes | | |
27 | * +----------------------+- - -+--------------------------------+ | |
28 | * nlmsg_attrdata(nlh, hdrlen)---^ | |
29 | * | |
30 | * Data Structures: | |
31 | * struct nlmsghdr netlink message header | |
32 | * | |
33 | * Message Construction: | |
34 | * nlmsg_new() create a new netlink message | |
35 | * nlmsg_put() add a netlink message to an skb | |
36 | * nlmsg_put_answer() callback based nlmsg_put() | |
37 | * nlmsg_end() finanlize netlink message | |
fe4944e5 TG |
38 | * nlmsg_get_pos() return current position in message |
39 | * nlmsg_trim() trim part of message | |
bfa83a9e TG |
40 | * nlmsg_cancel() cancel message construction |
41 | * nlmsg_free() free a netlink message | |
42 | * | |
43 | * Message Sending: | |
44 | * nlmsg_multicast() multicast message to several groups | |
45 | * nlmsg_unicast() unicast a message to a single socket | |
d387f6ad | 46 | * nlmsg_notify() send notification message |
bfa83a9e TG |
47 | * |
48 | * Message Length Calculations: | |
49 | * nlmsg_msg_size(payload) length of message w/o padding | |
50 | * nlmsg_total_size(payload) length of message w/ padding | |
51 | * nlmsg_padlen(payload) length of padding at tail | |
52 | * | |
53 | * Message Payload Access: | |
54 | * nlmsg_data(nlh) head of message payload | |
55 | * nlmsg_len(nlh) length of message payload | |
56 | * nlmsg_attrdata(nlh, hdrlen) head of attributes data | |
57 | * nlmsg_attrlen(nlh, hdrlen) length of attributes data | |
58 | * | |
59 | * Message Parsing: | |
60 | * nlmsg_ok(nlh, remaining) does nlh fit into remaining bytes? | |
61 | * nlmsg_next(nlh, remaining) get next netlink message | |
62 | * nlmsg_parse() parse attributes of a message | |
63 | * nlmsg_find_attr() find an attribute in a message | |
64 | * nlmsg_for_each_msg() loop over all messages | |
65 | * nlmsg_validate() validate netlink message incl. attrs | |
66 | * nlmsg_for_each_attr() loop over all attributes | |
67 | * | |
97676b6b TG |
68 | * Misc: |
69 | * nlmsg_report() report back to application? | |
70 | * | |
bfa83a9e TG |
71 | * ------------------------------------------------------------------------ |
72 | * Attributes Interface | |
73 | * ------------------------------------------------------------------------ | |
74 | * | |
75 | * Attribute Format: | |
76 | * <------- nla_total_size(payload) -------> | |
77 | * <---- nla_attr_size(payload) -----> | |
78 | * +----------+- - -+- - - - - - - - - +- - -+-------- - - | |
79 | * | Header | Pad | Payload | Pad | Header | |
80 | * +----------+- - -+- - - - - - - - - +- - -+-------- - - | |
81 | * <- nla_len(nla) -> ^ | |
82 | * nla_data(nla)----^ | | |
83 | * nla_next(nla)-----------------------------' | |
84 | * | |
85 | * Data Structures: | |
86 | * struct nlattr netlink attribtue header | |
87 | * | |
88 | * Attribute Construction: | |
fe4944e5 TG |
89 | * nla_reserve(skb, type, len) reserve room for an attribute |
90 | * nla_reserve_nohdr(skb, len) reserve room for an attribute w/o hdr | |
bfa83a9e | 91 | * nla_put(skb, type, len, data) add attribute to skb |
fe4944e5 | 92 | * nla_put_nohdr(skb, len, data) add attribute w/o hdr |
bfa83a9e TG |
93 | * |
94 | * Attribute Construction for Basic Types: | |
95 | * nla_put_u8(skb, type, value) add u8 attribute to skb | |
96 | * nla_put_u16(skb, type, value) add u16 attribute to skb | |
97 | * nla_put_u32(skb, type, value) add u32 attribute to skb | |
98 | * nla_put_u64(skb, type, value) add u64 attribute to skb | |
99 | * nla_put_string(skb, type, str) add string attribute to skb | |
100 | * nla_put_flag(skb, type) add flag attribute to skb | |
101 | * nla_put_msecs(skb, type, jiffies) add msecs attribute to skb | |
102 | * | |
103 | * Exceptions Based Attribute Construction: | |
104 | * NLA_PUT(skb, type, len, data) add attribute to skb | |
105 | * NLA_PUT_U8(skb, type, value) add u8 attribute to skb | |
106 | * NLA_PUT_U16(skb, type, value) add u16 attribute to skb | |
107 | * NLA_PUT_U32(skb, type, value) add u32 attribute to skb | |
108 | * NLA_PUT_U64(skb, type, value) add u64 attribute to skb | |
109 | * NLA_PUT_STRING(skb, type, str) add string attribute to skb | |
110 | * NLA_PUT_FLAG(skb, type) add flag attribute to skb | |
111 | * NLA_PUT_MSECS(skb, type, jiffies) add msecs attribute to skb | |
112 | * | |
113 | * The meaning of these functions is equal to their lower case | |
114 | * variants but they jump to the label nla_put_failure in case | |
115 | * of a failure. | |
116 | * | |
117 | * Nested Attributes Construction: | |
118 | * nla_nest_start(skb, type) start a nested attribute | |
119 | * nla_nest_end(skb, nla) finalize a nested attribute | |
120 | * nla_nest_cancel(skb, nla) cancel nested attribute construction | |
121 | * | |
122 | * Attribute Length Calculations: | |
123 | * nla_attr_size(payload) length of attribute w/o padding | |
124 | * nla_total_size(payload) length of attribute w/ padding | |
125 | * nla_padlen(payload) length of padding | |
126 | * | |
127 | * Attribute Payload Access: | |
128 | * nla_data(nla) head of attribute payload | |
129 | * nla_len(nla) length of attribute payload | |
130 | * | |
131 | * Attribute Payload Access for Basic Types: | |
132 | * nla_get_u8(nla) get payload for a u8 attribute | |
133 | * nla_get_u16(nla) get payload for a u16 attribute | |
134 | * nla_get_u32(nla) get payload for a u32 attribute | |
135 | * nla_get_u64(nla) get payload for a u64 attribute | |
136 | * nla_get_flag(nla) return 1 if flag is true | |
137 | * nla_get_msecs(nla) get payload for a msecs attribute | |
138 | * | |
139 | * Attribute Misc: | |
140 | * nla_memcpy(dest, nla, count) copy attribute into memory | |
141 | * nla_memcmp(nla, data, size) compare attribute with memory area | |
142 | * nla_strlcpy(dst, nla, size) copy attribute to a sized string | |
143 | * nla_strcmp(nla, str) compare attribute with string | |
144 | * | |
145 | * Attribute Parsing: | |
146 | * nla_ok(nla, remaining) does nla fit into remaining bytes? | |
147 | * nla_next(nla, remaining) get next netlink attribute | |
148 | * nla_validate() validate a stream of attributes | |
149 | * nla_find() find attribute in stream of attributes | |
fe4944e5 | 150 | * nla_find_nested() find attribute in nested attributes |
bfa83a9e TG |
151 | * nla_parse() parse and validate stream of attrs |
152 | * nla_parse_nested() parse nested attribuets | |
153 | * nla_for_each_attr() loop over all attributes | |
22acb19a | 154 | * nla_for_each_nested() loop over the nested attributes |
bfa83a9e TG |
155 | *========================================================================= |
156 | */ | |
157 | ||
158 | /** | |
159 | * Standard attribute types to specify validation policy | |
160 | */ | |
161 | enum { | |
162 | NLA_UNSPEC, | |
163 | NLA_U8, | |
164 | NLA_U16, | |
165 | NLA_U32, | |
166 | NLA_U64, | |
167 | NLA_STRING, | |
168 | NLA_FLAG, | |
169 | NLA_MSECS, | |
170 | NLA_NESTED, | |
a5531a5d | 171 | NLA_NUL_STRING, |
bfa83a9e TG |
172 | __NLA_TYPE_MAX, |
173 | }; | |
174 | ||
175 | #define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1) | |
176 | ||
177 | /** | |
178 | * struct nla_policy - attribute validation policy | |
179 | * @type: Type of attribute or NLA_UNSPEC | |
a5531a5d | 180 | * @len: Type specific length of payload |
bfa83a9e TG |
181 | * |
182 | * Policies are defined as arrays of this struct, the array must be | |
183 | * accessible by attribute type up to the highest identifier to be expected. | |
184 | * | |
a5531a5d TG |
185 | * Meaning of `len' field: |
186 | * NLA_STRING Maximum length of string | |
187 | * NLA_NUL_STRING Maximum length of string (excluding NUL) | |
188 | * NLA_FLAG Unused | |
189 | * All other Exact length of attribute payload | |
190 | * | |
bfa83a9e TG |
191 | * Example: |
192 | * static struct nla_policy my_policy[ATTR_MAX+1] __read_mostly = { | |
193 | * [ATTR_FOO] = { .type = NLA_U16 }, | |
a5531a5d TG |
194 | * [ATTR_BAR] = { .type = NLA_STRING, len = BARSIZ }, |
195 | * [ATTR_BAZ] = { .len = sizeof(struct mystruct) }, | |
bfa83a9e TG |
196 | * }; |
197 | */ | |
198 | struct nla_policy { | |
199 | u16 type; | |
a5531a5d | 200 | u16 len; |
bfa83a9e TG |
201 | }; |
202 | ||
4e902c57 TG |
203 | /** |
204 | * struct nl_info - netlink source information | |
205 | * @nlh: Netlink message header of original request | |
206 | * @pid: Netlink PID of requesting application | |
207 | */ | |
208 | struct nl_info { | |
209 | struct nlmsghdr *nlh; | |
210 | u32 pid; | |
211 | }; | |
212 | ||
82ace47a TG |
213 | extern void netlink_run_queue(struct sock *sk, unsigned int *qlen, |
214 | int (*cb)(struct sk_buff *, | |
215 | struct nlmsghdr *, int *)); | |
216 | extern void netlink_queue_skip(struct nlmsghdr *nlh, | |
217 | struct sk_buff *skb); | |
97676b6b TG |
218 | extern int nlmsg_notify(struct sock *sk, struct sk_buff *skb, |
219 | u32 pid, unsigned int group, int report, | |
220 | gfp_t flags); | |
82ace47a | 221 | |
bfa83a9e TG |
222 | extern int nla_validate(struct nlattr *head, int len, int maxtype, |
223 | struct nla_policy *policy); | |
224 | extern int nla_parse(struct nlattr *tb[], int maxtype, | |
225 | struct nlattr *head, int len, | |
226 | struct nla_policy *policy); | |
227 | extern struct nlattr * nla_find(struct nlattr *head, int len, int attrtype); | |
228 | extern size_t nla_strlcpy(char *dst, const struct nlattr *nla, | |
229 | size_t dstsize); | |
230 | extern int nla_memcpy(void *dest, struct nlattr *src, int count); | |
231 | extern int nla_memcmp(const struct nlattr *nla, const void *data, | |
232 | size_t size); | |
233 | extern int nla_strcmp(const struct nlattr *nla, const char *str); | |
234 | extern struct nlattr * __nla_reserve(struct sk_buff *skb, int attrtype, | |
235 | int attrlen); | |
fe4944e5 | 236 | extern void * __nla_reserve_nohdr(struct sk_buff *skb, int attrlen); |
bfa83a9e TG |
237 | extern struct nlattr * nla_reserve(struct sk_buff *skb, int attrtype, |
238 | int attrlen); | |
fe4944e5 | 239 | extern void * nla_reserve_nohdr(struct sk_buff *skb, int attrlen); |
bfa83a9e TG |
240 | extern void __nla_put(struct sk_buff *skb, int attrtype, |
241 | int attrlen, const void *data); | |
fe4944e5 TG |
242 | extern void __nla_put_nohdr(struct sk_buff *skb, int attrlen, |
243 | const void *data); | |
bfa83a9e TG |
244 | extern int nla_put(struct sk_buff *skb, int attrtype, |
245 | int attrlen, const void *data); | |
fe4944e5 TG |
246 | extern int nla_put_nohdr(struct sk_buff *skb, int attrlen, |
247 | const void *data); | |
bfa83a9e TG |
248 | |
249 | /************************************************************************** | |
250 | * Netlink Messages | |
251 | **************************************************************************/ | |
252 | ||
253 | /** | |
254 | * nlmsg_msg_size - length of netlink message not including padding | |
255 | * @payload: length of message payload | |
256 | */ | |
257 | static inline int nlmsg_msg_size(int payload) | |
258 | { | |
259 | return NLMSG_HDRLEN + payload; | |
260 | } | |
261 | ||
262 | /** | |
263 | * nlmsg_total_size - length of netlink message including padding | |
264 | * @payload: length of message payload | |
265 | */ | |
266 | static inline int nlmsg_total_size(int payload) | |
267 | { | |
268 | return NLMSG_ALIGN(nlmsg_msg_size(payload)); | |
269 | } | |
270 | ||
271 | /** | |
272 | * nlmsg_padlen - length of padding at the message's tail | |
273 | * @payload: length of message payload | |
274 | */ | |
275 | static inline int nlmsg_padlen(int payload) | |
276 | { | |
277 | return nlmsg_total_size(payload) - nlmsg_msg_size(payload); | |
278 | } | |
279 | ||
280 | /** | |
281 | * nlmsg_data - head of message payload | |
282 | * @nlh: netlink messsage header | |
283 | */ | |
284 | static inline void *nlmsg_data(const struct nlmsghdr *nlh) | |
285 | { | |
286 | return (unsigned char *) nlh + NLMSG_HDRLEN; | |
287 | } | |
288 | ||
289 | /** | |
290 | * nlmsg_len - length of message payload | |
291 | * @nlh: netlink message header | |
292 | */ | |
293 | static inline int nlmsg_len(const struct nlmsghdr *nlh) | |
294 | { | |
295 | return nlh->nlmsg_len - NLMSG_HDRLEN; | |
296 | } | |
297 | ||
298 | /** | |
299 | * nlmsg_attrdata - head of attributes data | |
300 | * @nlh: netlink message header | |
301 | * @hdrlen: length of family specific header | |
302 | */ | |
303 | static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, | |
304 | int hdrlen) | |
305 | { | |
306 | unsigned char *data = nlmsg_data(nlh); | |
307 | return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); | |
308 | } | |
309 | ||
310 | /** | |
311 | * nlmsg_attrlen - length of attributes data | |
312 | * @nlh: netlink message header | |
313 | * @hdrlen: length of family specific header | |
314 | */ | |
315 | static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen) | |
316 | { | |
317 | return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); | |
318 | } | |
319 | ||
320 | /** | |
321 | * nlmsg_ok - check if the netlink message fits into the remaining bytes | |
322 | * @nlh: netlink message header | |
323 | * @remaining: number of bytes remaining in message stream | |
324 | */ | |
325 | static inline int nlmsg_ok(const struct nlmsghdr *nlh, int remaining) | |
326 | { | |
327 | return (remaining >= sizeof(struct nlmsghdr) && | |
328 | nlh->nlmsg_len >= sizeof(struct nlmsghdr) && | |
329 | nlh->nlmsg_len <= remaining); | |
330 | } | |
331 | ||
332 | /** | |
333 | * nlmsg_next - next netlink message in message stream | |
334 | * @nlh: netlink message header | |
335 | * @remaining: number of bytes remaining in message stream | |
336 | * | |
337 | * Returns the next netlink message in the message stream and | |
338 | * decrements remaining by the size of the current message. | |
339 | */ | |
340 | static inline struct nlmsghdr *nlmsg_next(struct nlmsghdr *nlh, int *remaining) | |
341 | { | |
342 | int totlen = NLMSG_ALIGN(nlh->nlmsg_len); | |
343 | ||
344 | *remaining -= totlen; | |
345 | ||
346 | return (struct nlmsghdr *) ((unsigned char *) nlh + totlen); | |
347 | } | |
348 | ||
349 | /** | |
350 | * nlmsg_parse - parse attributes of a netlink message | |
351 | * @nlh: netlink message header | |
352 | * @hdrlen: length of family specific header | |
353 | * @tb: destination array with maxtype+1 elements | |
354 | * @maxtype: maximum attribute type to be expected | |
355 | * @policy: validation policy | |
356 | * | |
357 | * See nla_parse() | |
358 | */ | |
359 | static inline int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen, | |
360 | struct nlattr *tb[], int maxtype, | |
361 | struct nla_policy *policy) | |
362 | { | |
363 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | |
364 | return -EINVAL; | |
365 | ||
366 | return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), | |
367 | nlmsg_attrlen(nlh, hdrlen), policy); | |
368 | } | |
369 | ||
370 | /** | |
371 | * nlmsg_find_attr - find a specific attribute in a netlink message | |
372 | * @nlh: netlink message header | |
373 | * @hdrlen: length of familiy specific header | |
374 | * @attrtype: type of attribute to look for | |
375 | * | |
376 | * Returns the first attribute which matches the specified type. | |
377 | */ | |
378 | static inline struct nlattr *nlmsg_find_attr(struct nlmsghdr *nlh, | |
379 | int hdrlen, int attrtype) | |
380 | { | |
381 | return nla_find(nlmsg_attrdata(nlh, hdrlen), | |
382 | nlmsg_attrlen(nlh, hdrlen), attrtype); | |
383 | } | |
384 | ||
385 | /** | |
386 | * nlmsg_validate - validate a netlink message including attributes | |
387 | * @nlh: netlinket message header | |
388 | * @hdrlen: length of familiy specific header | |
389 | * @maxtype: maximum attribute type to be expected | |
390 | * @policy: validation policy | |
391 | */ | |
392 | static inline int nlmsg_validate(struct nlmsghdr *nlh, int hdrlen, int maxtype, | |
393 | struct nla_policy *policy) | |
394 | { | |
395 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | |
396 | return -EINVAL; | |
397 | ||
398 | return nla_validate(nlmsg_attrdata(nlh, hdrlen), | |
399 | nlmsg_attrlen(nlh, hdrlen), maxtype, policy); | |
400 | } | |
401 | ||
97676b6b TG |
402 | /** |
403 | * nlmsg_report - need to report back to application? | |
404 | * @nlh: netlink message header | |
405 | * | |
406 | * Returns 1 if a report back to the application is requested. | |
407 | */ | |
408 | static inline int nlmsg_report(struct nlmsghdr *nlh) | |
409 | { | |
410 | return !!(nlh->nlmsg_flags & NLM_F_ECHO); | |
411 | } | |
412 | ||
bfa83a9e TG |
413 | /** |
414 | * nlmsg_for_each_attr - iterate over a stream of attributes | |
415 | * @pos: loop counter, set to current attribute | |
416 | * @nlh: netlink message header | |
417 | * @hdrlen: length of familiy specific header | |
418 | * @rem: initialized to len, holds bytes currently remaining in stream | |
419 | */ | |
420 | #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \ | |
421 | nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ | |
422 | nlmsg_attrlen(nlh, hdrlen), rem) | |
423 | ||
424 | #if 0 | |
425 | /* FIXME: Enable once all users have been converted */ | |
426 | ||
427 | /** | |
428 | * __nlmsg_put - Add a new netlink message to an skb | |
429 | * @skb: socket buffer to store message in | |
430 | * @pid: netlink process id | |
431 | * @seq: sequence number of message | |
432 | * @type: message type | |
433 | * @payload: length of message payload | |
434 | * @flags: message flags | |
435 | * | |
436 | * The caller is responsible to ensure that the skb provides enough | |
437 | * tailroom for both the netlink header and payload. | |
438 | */ | |
439 | static inline struct nlmsghdr *__nlmsg_put(struct sk_buff *skb, u32 pid, | |
440 | u32 seq, int type, int payload, | |
441 | int flags) | |
442 | { | |
443 | struct nlmsghdr *nlh; | |
444 | ||
445 | nlh = (struct nlmsghdr *) skb_put(skb, nlmsg_total_size(payload)); | |
446 | nlh->nlmsg_type = type; | |
447 | nlh->nlmsg_len = nlmsg_msg_size(payload); | |
448 | nlh->nlmsg_flags = flags; | |
449 | nlh->nlmsg_pid = pid; | |
450 | nlh->nlmsg_seq = seq; | |
451 | ||
452 | memset((unsigned char *) nlmsg_data(nlh) + payload, 0, | |
453 | nlmsg_padlen(payload)); | |
454 | ||
455 | return nlh; | |
456 | } | |
457 | #endif | |
458 | ||
459 | /** | |
460 | * nlmsg_put - Add a new netlink message to an skb | |
461 | * @skb: socket buffer to store message in | |
462 | * @pid: netlink process id | |
463 | * @seq: sequence number of message | |
464 | * @type: message type | |
465 | * @payload: length of message payload | |
466 | * @flags: message flags | |
467 | * | |
468 | * Returns NULL if the tailroom of the skb is insufficient to store | |
469 | * the message header and payload. | |
470 | */ | |
471 | static inline struct nlmsghdr *nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, | |
472 | int type, int payload, int flags) | |
473 | { | |
474 | if (unlikely(skb_tailroom(skb) < nlmsg_total_size(payload))) | |
475 | return NULL; | |
476 | ||
477 | return __nlmsg_put(skb, pid, seq, type, payload, flags); | |
478 | } | |
479 | ||
480 | /** | |
481 | * nlmsg_put_answer - Add a new callback based netlink message to an skb | |
482 | * @skb: socket buffer to store message in | |
483 | * @cb: netlink callback | |
484 | * @type: message type | |
485 | * @payload: length of message payload | |
486 | * @flags: message flags | |
487 | * | |
488 | * Returns NULL if the tailroom of the skb is insufficient to store | |
489 | * the message header and payload. | |
490 | */ | |
491 | static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb, | |
492 | struct netlink_callback *cb, | |
493 | int type, int payload, | |
494 | int flags) | |
495 | { | |
496 | return nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, | |
497 | type, payload, flags); | |
498 | } | |
499 | ||
500 | /** | |
501 | * nlmsg_new - Allocate a new netlink message | |
502 | * @size: maximum size of message | |
fe4944e5 | 503 | * @flags: the type of memory to allocate. |
bfa83a9e TG |
504 | * |
505 | * Use NLMSG_GOODSIZE if size isn't know and you need a good default size. | |
506 | */ | |
fe4944e5 | 507 | static inline struct sk_buff *nlmsg_new(int size, gfp_t flags) |
bfa83a9e | 508 | { |
fe4944e5 | 509 | return alloc_skb(size, flags); |
bfa83a9e TG |
510 | } |
511 | ||
512 | /** | |
513 | * nlmsg_end - Finalize a netlink message | |
514 | * @skb: socket buffer the message is stored in | |
515 | * @nlh: netlink message header | |
516 | * | |
517 | * Corrects the netlink message header to include the appeneded | |
518 | * attributes. Only necessary if attributes have been added to | |
519 | * the message. | |
520 | * | |
521 | * Returns the total data length of the skb. | |
522 | */ | |
523 | static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh) | |
524 | { | |
525 | nlh->nlmsg_len = skb->tail - (unsigned char *) nlh; | |
526 | ||
527 | return skb->len; | |
528 | } | |
529 | ||
fe4944e5 TG |
530 | /** |
531 | * nlmsg_get_pos - return current position in netlink message | |
532 | * @skb: socket buffer the message is stored in | |
533 | * | |
534 | * Returns a pointer to the current tail of the message. | |
535 | */ | |
536 | static inline void *nlmsg_get_pos(struct sk_buff *skb) | |
537 | { | |
538 | return skb->tail; | |
539 | } | |
540 | ||
541 | /** | |
542 | * nlmsg_trim - Trim message to a mark | |
543 | * @skb: socket buffer the message is stored in | |
544 | * @mark: mark to trim to | |
545 | * | |
546 | * Trims the message to the provided mark. Returns -1. | |
547 | */ | |
548 | static inline int nlmsg_trim(struct sk_buff *skb, void *mark) | |
549 | { | |
550 | if (mark) | |
551 | skb_trim(skb, (unsigned char *) mark - skb->data); | |
552 | ||
553 | return -1; | |
554 | } | |
555 | ||
bfa83a9e TG |
556 | /** |
557 | * nlmsg_cancel - Cancel construction of a netlink message | |
558 | * @skb: socket buffer the message is stored in | |
559 | * @nlh: netlink message header | |
560 | * | |
561 | * Removes the complete netlink message including all | |
562 | * attributes from the socket buffer again. Returns -1. | |
563 | */ | |
564 | static inline int nlmsg_cancel(struct sk_buff *skb, struct nlmsghdr *nlh) | |
565 | { | |
fe4944e5 | 566 | return nlmsg_trim(skb, nlh); |
bfa83a9e TG |
567 | } |
568 | ||
569 | /** | |
570 | * nlmsg_free - free a netlink message | |
571 | * @skb: socket buffer of netlink message | |
572 | */ | |
573 | static inline void nlmsg_free(struct sk_buff *skb) | |
574 | { | |
575 | kfree_skb(skb); | |
576 | } | |
577 | ||
578 | /** | |
579 | * nlmsg_multicast - multicast a netlink message | |
580 | * @sk: netlink socket to spread messages to | |
581 | * @skb: netlink message as socket buffer | |
582 | * @pid: own netlink pid to avoid sending to yourself | |
583 | * @group: multicast group id | |
d387f6ad | 584 | * @flags: allocation flags |
bfa83a9e TG |
585 | */ |
586 | static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb, | |
d387f6ad | 587 | u32 pid, unsigned int group, gfp_t flags) |
bfa83a9e TG |
588 | { |
589 | int err; | |
590 | ||
591 | NETLINK_CB(skb).dst_group = group; | |
592 | ||
d387f6ad | 593 | err = netlink_broadcast(sk, skb, pid, group, flags); |
bfa83a9e TG |
594 | if (err > 0) |
595 | err = 0; | |
596 | ||
597 | return err; | |
598 | } | |
599 | ||
600 | /** | |
601 | * nlmsg_unicast - unicast a netlink message | |
602 | * @sk: netlink socket to spread message to | |
603 | * @skb: netlink message as socket buffer | |
604 | * @pid: netlink pid of the destination socket | |
605 | */ | |
606 | static inline int nlmsg_unicast(struct sock *sk, struct sk_buff *skb, u32 pid) | |
607 | { | |
608 | int err; | |
609 | ||
610 | err = netlink_unicast(sk, skb, pid, MSG_DONTWAIT); | |
611 | if (err > 0) | |
612 | err = 0; | |
613 | ||
614 | return err; | |
615 | } | |
616 | ||
617 | /** | |
618 | * nlmsg_for_each_msg - iterate over a stream of messages | |
619 | * @pos: loop counter, set to current message | |
620 | * @head: head of message stream | |
621 | * @len: length of message stream | |
622 | * @rem: initialized to len, holds bytes currently remaining in stream | |
623 | */ | |
624 | #define nlmsg_for_each_msg(pos, head, len, rem) \ | |
625 | for (pos = head, rem = len; \ | |
626 | nlmsg_ok(pos, rem); \ | |
627 | pos = nlmsg_next(pos, &(rem))) | |
628 | ||
629 | /************************************************************************** | |
630 | * Netlink Attributes | |
631 | **************************************************************************/ | |
632 | ||
633 | /** | |
634 | * nla_attr_size - length of attribute not including padding | |
635 | * @payload: length of payload | |
636 | */ | |
637 | static inline int nla_attr_size(int payload) | |
638 | { | |
639 | return NLA_HDRLEN + payload; | |
640 | } | |
641 | ||
642 | /** | |
643 | * nla_total_size - total length of attribute including padding | |
644 | * @payload: length of payload | |
645 | */ | |
646 | static inline int nla_total_size(int payload) | |
647 | { | |
648 | return NLA_ALIGN(nla_attr_size(payload)); | |
649 | } | |
650 | ||
651 | /** | |
652 | * nla_padlen - length of padding at the tail of attribute | |
653 | * @payload: length of payload | |
654 | */ | |
655 | static inline int nla_padlen(int payload) | |
656 | { | |
657 | return nla_total_size(payload) - nla_attr_size(payload); | |
658 | } | |
659 | ||
660 | /** | |
661 | * nla_data - head of payload | |
662 | * @nla: netlink attribute | |
663 | */ | |
664 | static inline void *nla_data(const struct nlattr *nla) | |
665 | { | |
666 | return (char *) nla + NLA_HDRLEN; | |
667 | } | |
668 | ||
669 | /** | |
670 | * nla_len - length of payload | |
671 | * @nla: netlink attribute | |
672 | */ | |
673 | static inline int nla_len(const struct nlattr *nla) | |
674 | { | |
675 | return nla->nla_len - NLA_HDRLEN; | |
676 | } | |
677 | ||
678 | /** | |
679 | * nla_ok - check if the netlink attribute fits into the remaining bytes | |
680 | * @nla: netlink attribute | |
681 | * @remaining: number of bytes remaining in attribute stream | |
682 | */ | |
683 | static inline int nla_ok(const struct nlattr *nla, int remaining) | |
684 | { | |
685 | return remaining >= sizeof(*nla) && | |
686 | nla->nla_len >= sizeof(*nla) && | |
687 | nla->nla_len <= remaining; | |
688 | } | |
689 | ||
690 | /** | |
691 | * nla_next - next netlink attribte in attribute stream | |
692 | * @nla: netlink attribute | |
693 | * @remaining: number of bytes remaining in attribute stream | |
694 | * | |
695 | * Returns the next netlink attribute in the attribute stream and | |
696 | * decrements remaining by the size of the current attribute. | |
697 | */ | |
698 | static inline struct nlattr *nla_next(const struct nlattr *nla, int *remaining) | |
699 | { | |
700 | int totlen = NLA_ALIGN(nla->nla_len); | |
701 | ||
702 | *remaining -= totlen; | |
703 | return (struct nlattr *) ((char *) nla + totlen); | |
704 | } | |
705 | ||
fe4944e5 TG |
706 | /** |
707 | * nla_find_nested - find attribute in a set of nested attributes | |
708 | * @nla: attribute containing the nested attributes | |
709 | * @attrtype: type of attribute to look for | |
710 | * | |
711 | * Returns the first attribute which matches the specified type. | |
712 | */ | |
713 | static inline struct nlattr *nla_find_nested(struct nlattr *nla, int attrtype) | |
714 | { | |
715 | return nla_find(nla_data(nla), nla_len(nla), attrtype); | |
716 | } | |
717 | ||
bfa83a9e TG |
718 | /** |
719 | * nla_parse_nested - parse nested attributes | |
720 | * @tb: destination array with maxtype+1 elements | |
721 | * @maxtype: maximum attribute type to be expected | |
722 | * @nla: attribute containing the nested attributes | |
723 | * @policy: validation policy | |
724 | * | |
725 | * See nla_parse() | |
726 | */ | |
727 | static inline int nla_parse_nested(struct nlattr *tb[], int maxtype, | |
728 | struct nlattr *nla, | |
729 | struct nla_policy *policy) | |
730 | { | |
731 | return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy); | |
732 | } | |
733 | /** | |
734 | * nla_put_u8 - Add a u16 netlink attribute to a socket buffer | |
735 | * @skb: socket buffer to add attribute to | |
736 | * @attrtype: attribute type | |
737 | * @value: numeric value | |
738 | */ | |
739 | static inline int nla_put_u8(struct sk_buff *skb, int attrtype, u8 value) | |
740 | { | |
741 | return nla_put(skb, attrtype, sizeof(u8), &value); | |
742 | } | |
743 | ||
744 | /** | |
745 | * nla_put_u16 - Add a u16 netlink attribute to a socket buffer | |
746 | * @skb: socket buffer to add attribute to | |
747 | * @attrtype: attribute type | |
748 | * @value: numeric value | |
749 | */ | |
750 | static inline int nla_put_u16(struct sk_buff *skb, int attrtype, u16 value) | |
751 | { | |
752 | return nla_put(skb, attrtype, sizeof(u16), &value); | |
753 | } | |
754 | ||
755 | /** | |
756 | * nla_put_u32 - Add a u32 netlink attribute to a socket buffer | |
757 | * @skb: socket buffer to add attribute to | |
758 | * @attrtype: attribute type | |
759 | * @value: numeric value | |
760 | */ | |
761 | static inline int nla_put_u32(struct sk_buff *skb, int attrtype, u32 value) | |
762 | { | |
763 | return nla_put(skb, attrtype, sizeof(u32), &value); | |
764 | } | |
765 | ||
766 | /** | |
767 | * nla_put_64 - Add a u64 netlink attribute to a socket buffer | |
768 | * @skb: socket buffer to add attribute to | |
769 | * @attrtype: attribute type | |
770 | * @value: numeric value | |
771 | */ | |
772 | static inline int nla_put_u64(struct sk_buff *skb, int attrtype, u64 value) | |
773 | { | |
774 | return nla_put(skb, attrtype, sizeof(u64), &value); | |
775 | } | |
776 | ||
777 | /** | |
778 | * nla_put_string - Add a string netlink attribute to a socket buffer | |
779 | * @skb: socket buffer to add attribute to | |
780 | * @attrtype: attribute type | |
781 | * @str: NUL terminated string | |
782 | */ | |
783 | static inline int nla_put_string(struct sk_buff *skb, int attrtype, | |
784 | const char *str) | |
785 | { | |
786 | return nla_put(skb, attrtype, strlen(str) + 1, str); | |
787 | } | |
788 | ||
789 | /** | |
790 | * nla_put_flag - Add a flag netlink attribute to a socket buffer | |
791 | * @skb: socket buffer to add attribute to | |
792 | * @attrtype: attribute type | |
793 | */ | |
794 | static inline int nla_put_flag(struct sk_buff *skb, int attrtype) | |
795 | { | |
796 | return nla_put(skb, attrtype, 0, NULL); | |
797 | } | |
798 | ||
799 | /** | |
800 | * nla_put_msecs - Add a msecs netlink attribute to a socket buffer | |
801 | * @skb: socket buffer to add attribute to | |
802 | * @attrtype: attribute type | |
803 | * @jiffies: number of msecs in jiffies | |
804 | */ | |
805 | static inline int nla_put_msecs(struct sk_buff *skb, int attrtype, | |
806 | unsigned long jiffies) | |
807 | { | |
808 | u64 tmp = jiffies_to_msecs(jiffies); | |
809 | return nla_put(skb, attrtype, sizeof(u64), &tmp); | |
810 | } | |
811 | ||
812 | #define NLA_PUT(skb, attrtype, attrlen, data) \ | |
813 | do { \ | |
814 | if (nla_put(skb, attrtype, attrlen, data) < 0) \ | |
815 | goto nla_put_failure; \ | |
816 | } while(0) | |
817 | ||
818 | #define NLA_PUT_TYPE(skb, type, attrtype, value) \ | |
819 | do { \ | |
820 | type __tmp = value; \ | |
821 | NLA_PUT(skb, attrtype, sizeof(type), &__tmp); \ | |
822 | } while(0) | |
823 | ||
824 | #define NLA_PUT_U8(skb, attrtype, value) \ | |
825 | NLA_PUT_TYPE(skb, u8, attrtype, value) | |
826 | ||
827 | #define NLA_PUT_U16(skb, attrtype, value) \ | |
828 | NLA_PUT_TYPE(skb, u16, attrtype, value) | |
829 | ||
830 | #define NLA_PUT_U32(skb, attrtype, value) \ | |
831 | NLA_PUT_TYPE(skb, u32, attrtype, value) | |
832 | ||
833 | #define NLA_PUT_U64(skb, attrtype, value) \ | |
834 | NLA_PUT_TYPE(skb, u64, attrtype, value) | |
835 | ||
836 | #define NLA_PUT_STRING(skb, attrtype, value) \ | |
837 | NLA_PUT(skb, attrtype, strlen(value) + 1, value) | |
838 | ||
ff5dfe73 | 839 | #define NLA_PUT_FLAG(skb, attrtype) \ |
bfa83a9e TG |
840 | NLA_PUT(skb, attrtype, 0, NULL) |
841 | ||
842 | #define NLA_PUT_MSECS(skb, attrtype, jiffies) \ | |
843 | NLA_PUT_U64(skb, attrtype, jiffies_to_msecs(jiffies)) | |
844 | ||
845 | /** | |
846 | * nla_get_u32 - return payload of u32 attribute | |
847 | * @nla: u32 netlink attribute | |
848 | */ | |
849 | static inline u32 nla_get_u32(struct nlattr *nla) | |
850 | { | |
851 | return *(u32 *) nla_data(nla); | |
852 | } | |
853 | ||
854 | /** | |
855 | * nla_get_u16 - return payload of u16 attribute | |
856 | * @nla: u16 netlink attribute | |
857 | */ | |
858 | static inline u16 nla_get_u16(struct nlattr *nla) | |
859 | { | |
860 | return *(u16 *) nla_data(nla); | |
861 | } | |
862 | ||
863 | /** | |
864 | * nla_get_u8 - return payload of u8 attribute | |
865 | * @nla: u8 netlink attribute | |
866 | */ | |
867 | static inline u8 nla_get_u8(struct nlattr *nla) | |
868 | { | |
869 | return *(u8 *) nla_data(nla); | |
870 | } | |
871 | ||
872 | /** | |
873 | * nla_get_u64 - return payload of u64 attribute | |
874 | * @nla: u64 netlink attribute | |
875 | */ | |
876 | static inline u64 nla_get_u64(struct nlattr *nla) | |
877 | { | |
878 | u64 tmp; | |
879 | ||
880 | nla_memcpy(&tmp, nla, sizeof(tmp)); | |
881 | ||
882 | return tmp; | |
883 | } | |
884 | ||
885 | /** | |
886 | * nla_get_flag - return payload of flag attribute | |
887 | * @nla: flag netlink attribute | |
888 | */ | |
889 | static inline int nla_get_flag(struct nlattr *nla) | |
890 | { | |
891 | return !!nla; | |
892 | } | |
893 | ||
894 | /** | |
895 | * nla_get_msecs - return payload of msecs attribute | |
896 | * @nla: msecs netlink attribute | |
897 | * | |
898 | * Returns the number of milliseconds in jiffies. | |
899 | */ | |
900 | static inline unsigned long nla_get_msecs(struct nlattr *nla) | |
901 | { | |
902 | u64 msecs = nla_get_u64(nla); | |
903 | ||
904 | return msecs_to_jiffies((unsigned long) msecs); | |
905 | } | |
906 | ||
907 | /** | |
908 | * nla_nest_start - Start a new level of nested attributes | |
909 | * @skb: socket buffer to add attributes to | |
910 | * @attrtype: attribute type of container | |
911 | * | |
912 | * Returns the container attribute | |
913 | */ | |
914 | static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype) | |
915 | { | |
916 | struct nlattr *start = (struct nlattr *) skb->tail; | |
917 | ||
918 | if (nla_put(skb, attrtype, 0, NULL) < 0) | |
919 | return NULL; | |
920 | ||
921 | return start; | |
922 | } | |
923 | ||
924 | /** | |
925 | * nla_nest_end - Finalize nesting of attributes | |
926 | * @skb: socket buffer the attribtues are stored in | |
927 | * @start: container attribute | |
928 | * | |
929 | * Corrects the container attribute header to include the all | |
930 | * appeneded attributes. | |
931 | * | |
932 | * Returns the total data length of the skb. | |
933 | */ | |
934 | static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start) | |
935 | { | |
936 | start->nla_len = skb->tail - (unsigned char *) start; | |
937 | return skb->len; | |
938 | } | |
939 | ||
940 | /** | |
941 | * nla_nest_cancel - Cancel nesting of attributes | |
942 | * @skb: socket buffer the message is stored in | |
943 | * @start: container attribute | |
944 | * | |
945 | * Removes the container attribute and including all nested | |
946 | * attributes. Returns -1. | |
947 | */ | |
948 | static inline int nla_nest_cancel(struct sk_buff *skb, struct nlattr *start) | |
949 | { | |
fe4944e5 | 950 | return nlmsg_trim(skb, start); |
bfa83a9e TG |
951 | } |
952 | ||
953 | /** | |
954 | * nla_for_each_attr - iterate over a stream of attributes | |
955 | * @pos: loop counter, set to current attribute | |
956 | * @head: head of attribute stream | |
957 | * @len: length of attribute stream | |
958 | * @rem: initialized to len, holds bytes currently remaining in stream | |
959 | */ | |
960 | #define nla_for_each_attr(pos, head, len, rem) \ | |
961 | for (pos = head, rem = len; \ | |
962 | nla_ok(pos, rem); \ | |
963 | pos = nla_next(pos, &(rem))) | |
964 | ||
fe4944e5 TG |
965 | /** |
966 | * nla_for_each_nested - iterate over nested attributes | |
967 | * @pos: loop counter, set to current attribute | |
968 | * @nla: attribute containing the nested attributes | |
969 | * @rem: initialized to len, holds bytes currently remaining in stream | |
970 | */ | |
971 | #define nla_for_each_nested(pos, nla, rem) \ | |
972 | nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem) | |
973 | ||
bfa83a9e | 974 | #endif |